Drop the crunches. Crunches suck. Start in with prone planks instead. And do side planks. For flexion try ab pulldowns or janda situps if you can get someone to hold your legs or rig it somehow, saxon side bends (db overhead side bends), cable woodchops, russian twists. Not all on the same day, lol
Bar rollouts or a regular ab roller would also be a good thing to do.
Watch your shoulders. If it hurts so much it may be that you are holding the bar wrong during squats.
I would think about taking out the middle squat ("wednesday") and putting in a single leg variant of some kind. Maybe static split squats to start with. This will be of great benefit and allow some recovery, help train the hips and cut down the chance of injury. Also reduce some of the total stress to make it easier to handle the workload.
If you're doing the A-B-A format...I say don't. It's stupid to set it up so that the stress changes form week to week. Deadlifts are going to be the most draining. Deadlifting twice some weeks is just going to result in bad mojo. Just go A-B-C...
If I had my druthers, I'd want you to not even start the program right now but instead give yourself a honeymoon period with the lifts. The things a true beginner is going to get stronger pretty much no matter what. Just a few weeks of learning the movements, honing in the movement patterns, etc., will produce noticeable improvements in "strength". To say nothing of improvements in recruitment.